1. Field of the Invention
The present invention relates to a portable transmitter, which is used to remotely control each corresponding vehicular device of a vehicle.
2. Description of Related Art
A keyless entry system has been known. In the known keyless entry system, locking/unlocking of a door or a rear hatch of a vehicle can be remotely controlled in response to operation of a button of a door lock transmitter (portable transmitter), which is carried by a user, such as a driver.
More specifically, in the keyless entry system, the door lock transmitter, which is operated by the user through operation of the button, performs radio transmission of a corresponding operation command (e.g., a command for locking or unlocking of the door). The operation command commands a corresponding vehicular device to provide the function that corresponds to the operated button. An in-vehicle apparatus, which receives the operation command, drives the corresponding vehicular device (e.g., a door lock actuator) to provide the specified function, which is specified by the operation command.
The function, which is provided through the operation of the button of the door lock transmitter, is not limited to the above locking/unlocking of the door, and there are other functions, which include opening/closing of a slide door, a power window, a sunroof and/or the like. To provide these functions, the door lock transmitter also includes other buttons.
The above structure of the door lock transmitter is generally known and is regarded as a previously known or previously used prior art in the field of the keyless entry system, so that no prior art document with respect to the above structure is recited herein.
Frequently used functions and easily operable button positions vary from user to user. The frequently used functions are not always allocated to buttons located in easily operable positions. In order to improve convenience of individual user, it is desirable to meet a demand for customizing allocation of the functions to the buttons when such a demand exists.
To meet such a demand, for example, it is conceivable to prepare various door lock transmitters, each of which has a different allocation pattern for allocating functions to buttons, and to provide one of the door lock transmitters, which has the allocation pattern that meets the user's need. Alternatively, it is also conceivable to perform reconstruction, such as change of a wiring of a print circuit board of the door lock transmitter based on the user's need. However, in the former case, a relatively large amount of work is required in designing and manufacturing of the door lock transmitters. Also, in the latter case, additional work is required upon the manufacturing of the door lock transmitter. Thus, in both of the above cases, manufacturing costs are disadvantageously increased.
Particularly, in the case of changing a pattern of the wiring, it is highly possible to cause a change in radio characteristics. Thus, even when such reconstruction is made, the door transmitter cannot be used properly in some cases.
Furthermore, even when such reconstruction is made, it is only possible to change the allocation pattern for allocating the preselected functions to the buttons, and it is not possible to select desired functions among various functions, which are controllable from the door lock transmitter.